A matrix-assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometer will be purchased and used to support the research of a multidisciplinary group of 11 laboratories including 9 NIH-funded researchers and users of the Protein Core Facility of the University of Illinois at Chicago. Approximately 80% of the instrument time will be utilized by NIH-funded major users, and the remaining time will be used by the Protein Core Facility and other researchers on campus and in the Chicago area. This instrument will be the first MALDI-TOF mass spectrometer at the University of Illinois at Chicago. The MALDI-TOF MS will be located in the College of Pharmacy on the medical campus of the University of Illinois at Chicago in recently renovated space under the supervision of the P.I. Access to the instrument by new users on and off campus will be assured through the administrative oversight of an advisory committee appointed by the Research Resources Center (RRC), which is a centralized campus instrumentation facility that has been in operation for over 50 years. The RRC will be recruiting a senior mass spectrometrist and additional personnel to assist with mass spectrometry services. One of these additional personnel will assist with the operation and maintenance of the new MALDI-TOF MS. Because this instrument operator will be a new employee of the University of Illinois at Chicago, this represents a new commitment by the RRC. In addition, the RRC will provide machine shop and electronics shop support for the MALDI-TOF mass spectrometer. These commitments represent substantial support by the RRC and the university. The P.I. already oversees the daily operation and maintenance of the existing RRC electrospray triple quadrupole mass spectrometer and has experience in laser desorption TOF mass spectrometry. User fees (determined by the advisory committee) will be collected to defray the costs of consumable supplies and repairs. Overall, the proposed MALDI-TOF mass spectrometer will complement the existing electrospray mass spectrometry instrumentation on campus and will enhance the current research of NIH-funded users by providing analytical capabilities currently unavailable anywhere at the University of Illinois at Chicago.